1. A wireless transmit/receive unit (WTRU) comprising:a processor configured to selectively enable and disable reception of downlink signaling and configured to monitor a buffer of the WTRU for data to transmit;
a transmitter configured to transmit, while reception of the downlink signaling is disabled, a channel allocation request in response to data in the monitored buffer;
the processor further configured, in response to the data in the monitored buffer, to enable reception of the downlink signaling to allow the WTRU to receive an uplink channel allocation;
the transmitter further configured, in response to the WTRU receiving an uplink channel allocation, to transmit uplink data on an uplink channel; and
the processor is further configured to track a time when hybrid automatic repeat request (HARQ) feedback is expected to be received in response to the transmitted uplink data, and configured to receive the HARQ feedback at the expected time.